I was trying to run http://code.dlang.org/packages/d-option but got a "terminated by signal SIGSEGV (Address boundary error)" with dmd v2.071.1. I suppose it is a regression, but that is assuming the library compiled during the last commit (~1 year ago).

I ran dustmite to get min. test case:

struct Option(T)
{
  auto opDispatch(Args...)() {
    alias R = typeof(MethodCall);
None!R;
  }

}

Option!T Some(T)(T )
;
T Some()() {
}
T None(T)()
{
}

unittest {
Some(1).flatten ;
}

I know the reduced code doesn't make any sense anymore. But this is what triggers the SIGSEGV